The present disclosure relates to an image forming apparatus provided with a conveying unit configured to form or open a conveying path.
An image forming apparatus, such as a copying machine and a printer, is generally configured to include an apparatus main body and a conveying unit provided at the apparatus main body in a turnable manner in an upper-and-lower direction. Between the apparatus main body and the conveying unit, a conveying path for a sheet is formed. When the conveying unit is turned upward, a hook provided at the conveying unit is engaged with a boss provided at the apparatus main body. Additionally, one resist roller and a secondary transferring roller provided at the conveying unit respectively come into contact with the other resist roller and an intermediate transferring belt provided at the apparatus main body to form the conveying path. On the other hand, when the conveying unit is turned downward, the hook is disengaged with the boss to open the conveying path.
In the image forming apparatus having such a configuration, just before the hook of the conveying unit is engaged with the boss of the apparatus main body, reaction force generated on the one resist roller and the secondary transferring roller pressed by the other resist roller and the intermediate transferring belt becomes large. This requires large force in order to engage the hook with the boss. For example, in a case where the hook is engaged with the boss by a spring, the spring requires large spring force.
However, if the force for engagement of the hook with the boss is made large simply, large force is required to disengage the hook with the boss and workability is deteriorated. Then, in some cases, the hook is secondarily pushed by an outer cover provided outside the conveying unit to engage the hook with the boss. In this case, because a direction in which the outer cover pushes the hook is the same as a turning direction of the conveying unit, a nip pressure between the one resist roller and the other resist roller and a nip pressure between the secondary transferring roller and the intermediate transferring belt are affected to cause sheet conveying failure or the like.